An RMAN backup job fails， displaying the following error message：  ORA/x7f19809： limit exceeded for recovery files  Your analysis shows that the Flash Recovery area is full. What would you do to resolve the error？（）

• A、increase the value of UNDO_RETENTION
• B、change the value of WORKAREA_SIZE_POLICY to AUTO
• C、increase the value of DB_RECOVERY_FILE_DEST_SIZE
• D、increase the value of CONTROL_FILE_RECORD_KEEP_TIME